MedlinePlus Medical Encyclopedia: Absence of menstruation (amenorrhea)

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Absence of menstruation (amenorrhea)

Amenorrhea is the lack of menstrual flow and can be a normal occurrence or a sign of malfunction or disease. In primary amenorrhea, menstruation does not begin when expected (by the age of 16). Secondary amenorrhea occurs when the normal established menstrual cycle is shut down for 6 or more months due to a condition other than pregnancy, breastfeeding or menopause.

Update Date: 9/11/2006

Updated by: J. Gordon Lambert, MD, Associate Medical Director; G. Eric Morgan, MS3; RxRemedy and A.D.A.M. Medical Illustration Team.

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